1. Field of the Invention
The present invention relates to a display panel, and more particularly to a liquid crystal display panel and a fabricating method thereof. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for preventing a ball spacer in the liquid crystal display panel from moving, and a fabricating method thereof.
2. Description of the Related Art
Generally, a liquid crystal display panel controls the light transmittance of an arrangement of liquid crystal molecules by use of electric field, thereby displaying a picture. FIG. 1 is a perspective plan view of a liquid crystal display panel according to the related art. The liquid crystal display panel, as shown in FIG. 1, includes a thin film transistor substrate 70 and a color filter substrate 80 that face each other with a layer of liquid crystal molecules 16 therebetween.
The color filter substrate 80 has a color filter array 12 of R, G and B filters for realizing color formed on an upper substrate 11. The color filter substrate 80 also includes a black matrix 18 for preventing light leakage between the color filters 12. A common electrode 14 is formed on the color filter array 12. An upper alignment film (not shown) can be formed on the common electrode 14 to provide initial alignment to the liquid crystal molecules 16.
Thin film transistor substrate 70 has a thin film transistor array formed on the lower substrate 1, including a gate line 2 and a data line 4 that cross each other, and a thin film transistor 30 formed in adjacent to the crossing of the gate and data lines 2 and 4. The thin film transistor array also includes a pixel electrode 22 connected to the thin film transistor 30. A lower alignment film (not shown) can be formed over the thin film transistor array to provide initial alignment to the liquid crystal molecules 16. The orientation of liquid crystal molecules is can be controlled by way an electric field between the common electrode 14 on the upper substrate 11 and the pixel electrode 22 on the lower substrate 1.
FIG. 2 is a cross-sectional view of a ball spacer that maintains a cell gap between a color filter substrate and a thin film transistor substrate according to the related art. As shown in FIG. 2, a ball spacer 13 maintains the cell gap between the color filter substrate 80 and the thin film transistor substrate 70. The ball spacer 13 is on either the gate line 2 or the data line (not shown) that is overlapped by the black matrix 18. The ball spacer 13 can be formed by using an ink jetting method.
Because the ball spacer 13 has a globular shape, the ball spacer 13 may move about the liquid crystal display panel as a result of an impact applied to the liquid crystal display panel from the outside. For example, the ball spacer 13 can be moved to a position other than its initially deposited position by an impact applied to the liquid crystal display panel during a process of sticking polarizers to the external surfaces of the lower substrate 1 and the upper substrate 11. In another example, the ball spacer 13 can be moved about due to a vibration/impact test, which is one of the reliability tests for liquid crystal display panels.
An out of position ball spacer 13 may cause light leakage by interfering with the control of liquid crystal molecules 16. A bright spot occurs in the liquid crystal display panel where such light leakage. The bright spot becomes a cause of a defect. Further, in the case of dislocated ball spacer 13 being positioned on the pixel electrode 22, i.e. in the display area, the aperture ratio decreases.